The present disclosure relates generally to medical devices and, more particularly, to medical monitoring devices.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
In the field of medicine doctors often desire to monitor certain physiological characteristics of their patients. Accordingly, a wide variety of devices have been developed for monitoring physiological characteristics. Such devices provide doctors and other healthcare personnel with the information they need to provide the best possible healthcare for their patients. As a result, such monitoring devices have become an indispensable part of modern medicine.
One technique for monitoring certain physiological characteristics of a patient is commonly referred to as pulse oximetry, and the devices built based upon pulse oximetry techniques are commonly referred to as pulse oximeters. Pulse oximetry may be used to measure various blood flow characteristics, such as the blood-oxygen saturation of hemoglobin in arterial blood, the volume of individual blood pulsations supplying the tissue, and/or the rate of blood pulsations corresponding to each heartbeat of a patient.
Pulse oximeters typically utilize a non-invasive sensor that is placed on or against a patient's tissue that is well perfused with blood, such as a patient's finger, toe, forehead or earlobe. The sensor is usually small, lightweight, and flexible so that it may be easily and comfortably held against the patient's tissue. The pulse oximeter sensor emits light and photoelectrically senses the absorption and/or scattering of the light after passage through the perfused tissue. The data collected by the sensor may then be used to calculate one or more of the above physiological characteristics based upon the absorption or scattering of the light. More specifically, the emitted light is typically selected to be of one or more wavelengths that are absorbed or scattered in an amount related to the presence of oxygenated versus de-oxygenated hemoglobin in the blood. The amount of light absorbed and/or scattered may then be used to estimate the amount of the oxygen in the tissue using various algorithms.
Due to the flexibility and small size of the pulse oximeter sensor, the amount of circuitry included in the sensor is usually rather limited. Accordingly, the sensor is usually coupled through a cable to a monitor that sends and receives electrical signals to the sensor and includes circuitry used for processing the received signals and performing other functions that are outside the limited capabilities of the sensor.
This conventional configuration, however, may have several disadvantages. For example, the cable may tend to pick up unwanted electrical noise, thereby reducing the signal-to-noise ratio of transmitted signal. For another example, the transmission of analog signals through the resistive cable may result in substantial power loss. For yet another example, the patient's comfort and mobility may be limited by the cable running between the sensor and the monitor. It may be desirable, therefore, to provide a medical sensor with improved processing functionality while maintaining the sensor's flexibility and comfort.